POS1011 THE STUDY OF DETECTION OF FECAL CALPROTECTIN AS A MARKER OF EARLY DIAGNOSIS OF THE DEVELOPMENT OF INFLAMMATORY BOWEL DISEASES IN PATIENTS WITH ANKYLOSING SPONDYLITIS
Authors: D. Tarasova, L. Shilova, A. Feoktistova
Journal: Annals of the Rheumatic Diseases (2022)

Background Ankylosing spondylitis (AS) can be characterized not only by the detection of the musculoskeletal system, but by the probable contribution of extraskeletal manifestations (ESMs), which can aggravate the course of the disease, and may occur in the first place in terms of the activity of the process. At the same time, according to the findings, in 3.5-10% of patients with AS, a diagnosis of IBD was detected, and in 70% of patients with AS, subclinical symptoms of intestinal disorders were detected. AS and IBD have common links of pathogenesis: microbiota and intestinal wall condition. Currently, highly sensitive fecal laboratory tests are used to monitor inflammation activity in IBD prior to ileocolonoscopy. Fecal calprotectin (FCP) is a marker of neutrophilic inflammation in gastrointestinal diseases and an indicator of the intensity of the inflammatory process in the intestine. The concentration of FCP is statistically significantly higher in IBD patients with signs of clinical activity and, as a rule, does not go beyond the normal range in patients with irritable bowel syndrome. These data make it possible to consider fecal calprotectin as a promising marker of the onset and latent course of inflammatory bowel disease in patients with ankylosing spondylitis. Objectives To reveal the peculiarities of fecal calprotectin concentration in patients with ankylosing spondylitis in case of occurrence and recurrence of inflammatory bowel diseases as extraskeletal manifestations. Methods The study included 80 patients with ankylosing spondylitis: women - 28 (35%), men - 52 (65%). The average age of patients was 45.12±12.4 years, the average age of onset symptoms - 28.43±13.18 years, mean duration of AS - 18.7±11.75 years. Patients already diagnosed with AS were asked to complete a questionnaire using the Universal Questionnaire to identify signs of immunoinflammatory diseases - psoriasis, psoriatic arthritis, IBD (Crohn’s disease, ulcerative colitis) to identify clinical signs of intestinal damage. With a positive answer to one main and one additional questions, the patient was asked to conduct a qualitative determination of fecal calprotectin. Before the study, patients were stopped taking non-steroidal anti-inflammatory drugs for two weeks. Patients in whom the presence of calprotectin in the feces was detected, at the next stage, a semi-quantitative determination of calprotectin in the feces was carried out by immunochromatographic method. Patients who had an increase in the concentration of fecal calprotectin above 200 µg/g were recommended to perform a diagnostic colonoscopy on an outpatient basis to clarify the diagnosis. The next step was the determination of fecal calprotectin in patients with a positive survey result. In 26 patients (32.5%) a positive result was revealed. Results In 71 (88.7%), according to the results of the questionnaire, subclinical signs of intestinal damage were identified. At the next stage, patients with a positive result in the determination of FCP underwent an immunochromatographic test to detect the concentration of calprotectin in the feces. Of these, 22 patients (84.6%) had a concentration of 50-200 µg/g, which indicates the need for dynamic monitoring of this group of patients. In 4 patients (15.38%), the concentration of PCP was found to be higher than 200 µg/g. Conclusion Аmong patients with ankylosing spondylitis, 88.7% have subclinical signs of intestinal damage. Of these, calprotectin is determined in feces in 32.5%, which may indicate a latent course or debut of inflammatory bowel disease. Determination of the presence of fecal calprotectin in patients with ankylosing spondylitis contributes to the early diagnosis of inflammatory bowel disease. Disclosure of Interests None declared